1. Technical Field of the Invention
This invention relates to a substrate processing apparatus and a substrate processing method. More in detail, the invention relates to substrate processing apparatus and method for processing substrates, for example, semiconductor wafers, glass substrates for LCD, etc. with a processing gas, such as ozone gas, the substrates being accommodated in a processing container capable of establishing a closed atmosphere therein.
2. Description of the Related Art
Generally, the manufacturing process for semiconductor devices comprises the following steps of: applying photo-resist on substrates, for example, semiconductor wafers and LCD baseplates; transferring a circuit pattern, which has been scaled down by the photo-lithography technique, to the above photo-resist; developing this pattern; and thereafter removing the photo-resist from the wafers etc. Note, the semiconductor wafers will be simply referred as xe2x80x9cwafersxe2x80x9d, hereinafter.
As means for removing the photo-resist, there exists a substrate cleaning apparatus. In the prior art cleaning apparatus, the operation to remove the photo-resist from the substrates is accomplished by dipping the wafers etc. into a cleaning bath filled up with a chemical liquid generally called xe2x80x9cSPMxe2x80x9d (mixture of H2SO4 and H2O2). To the contrary, there has been a general demand to use a solution of ozone (O3) for the removal operation since its effluent process from a factory is preferable in view of the protection of the environment. In using the solution of ozone (O3) for the removal operation, there is generally employed a cleaning method that the wafers etc. are dipped into a cleaning bath filled up with a solution having ozone melted thereinto, which is so-called xe2x80x9cdipxe2x80x9d type cleaning method. In this method, the photo-resist on the wafers is oxidized and dissolved into carbon dioxide and water etc. by oxygen atomic radicals in the solution.
Incidentally, according to the above-mentioned method, the ozone gas of high concentration is firstly dissolved into pure water in the form of bubbles thereby to produce the xe2x80x9cozonexe2x80x9d solution and thereafter, the resultant solution is supplied into the cleaning bath. Therefore, there sometimes arises a situation that ozone(s) in the solution gradually disappear during the transportation, so that the concentration of ozone is reduced to cause an insufficient removal of the photo-resist. Additionally, the removal operation by dipping the wafers etc. into the ozone solution cannot afford the reaction (oxidation of resist) at high speed. Because, the removal operation is apt to make the quantity of ozone(s) for the resist insufficient although ozone(s) successively disappears as the result of the reaction with the resist.
In place of such a cleaning method for cleaning the wafers etc. by dipping them into the ozone solution, there is newly proposed a cleaning (etching) method for removing the resist from the wafers etc. while using a processing gas, for example, mixture of ozone gas and vapor of solvent, for example, steam. Note, in this specification, the above vapor of solvent will be referred xe2x80x9csolvent vaporxe2x80x9d, hereinafter. According to this cleaning (etching) method, the processing gas, for example, ozone gas is supplied to the wafers accommodated in a closed processing container where the resist is removed from the wafers.
However, the substrate processing apparatus employing the above-mentioned cleaning method has problems to be solved. First, dewdrops of the solvent vapor are produced in a solvent-vapor nozzle disposed in the processing container, thereby causing sources of bacteria and particles. Second, the dewdrops are scattered to stick to the wafers at the time of ejecting the solvent vapor, thereby causing the wafers to be cleaned with unevenness. Additionally, the solvent vapor is condensed into dewdrops of water that sticks to an upside inner wall of the processing container. Then, the waterdrops fall onto the wafers to cause the sources of particles. Further, the dewdrops of water are scattered into the processing container, causing the wafers to be cleaned with unevenness.
Since the above-mentioned substrate processing apparatus includes a steam generator whose inside pressure is constant (almost atmospheric pressure), there exists a limit in producing the steam. Therefore, under a situation that an interior of the processing container is pressurized more than the atmospheric pressure, then a problem arises in that the quantity of solvent vapor to be supplied into the processing container decreases, so that the processing capability of the apparatus itself is lowered.
Under such a circumference as mentioned above, an object of the present invention is to provide a substrate processing apparatus that restricts the formation of dewdrops of the solvent vapor which may produce sources of particles etc. or cause cleaning (etching) unevenness etc. in the processing container thereby to improve the processing efficiency of the apparatus. Additionally, another object of the present invention is to provide substrate processing method and apparatus by which an amount of solvent vapor generated is so adjusted as to supply the processing container with an appropriate amount of solvent vapor thereby to improve the processing efficiency of the apparatus.
In order to attain the above objects, according to the first aspect of the present invention, there is provided a substrate processing apparatus for supplying a substrate to be processed with processing gas and solvent vapor, comprising:
a processing container for accommodating the substrate therein;
a processing-gas supplier for supplying the processing gas into the processing container;
a solvent-vapor generator for generating the solvent vapor to be supplied into the processing container; and
a solvent-vapor nozzle arranged in the processing container and also connected to the solvent-vapor generator,
wherein the solvent-vapor nozzle includes a nozzle body having a plurality of nozzle orifices formed at appropriate intervals and a condensation-proof mechanism for preventing dewdrops from being formed in an inside space of the nozzle body.
According to the second feature of the invention, the condensation-proof mechanism comprises a heater for heating the inside space of the nozzle body. Accordingly, it is possible to prevent the solvent-vapor from being condensed into dewdrops in the nozzle body. Also, there is no possibility that the dewdrops of water are scattered onto the substrates at the ejection of the solvent-vapor. Thus it is possible to restrict an outbreak of bacteria due to the formation of dewdrops in the nozzle body and an occurrence of particles due to the scattering of dewdrops.
According to the third feature of the invention, the condensation-proof mechanism comprises a drain port formed on the bottom of the nozzle body to communicate the inside space of the nozzle body with an outside thereof. Accordingly, the drain port can drain the dewdrops from the nozzle body to the outside, preventing the dewdrops of water from being scattered around at the ejection of the solvent-vapor. In connection, the nozzle body may be modified to have an inner pipe inserted thereinto through a clearance and also connected to the solvent-vapor generator, the inner pipe having communication holes formed on the opposite side of the nozzle orifices in the nozzle body. In such a case, the supplied solvent-vapor is ejected from the nozzle orifices after the vapor has entered into a clearance between the nozzle body and the inner pipe through the communication hole. Thus it is possible to eject the solvent-vapor from the nozzle orifices uniformly.
According to the fourth feature of the invention, the drain port is arranged on the side of one end of the nozzle body. The dewdrops collected on respective bottoms of the nozzle body and the inner pipe move toward the end of the nozzle body due to an ejection power of the solvent-vapor. Therefore, owing to the formation of the drain port on the side of the end of the nozzle body, it is possible to discharge the dewdrops of water with ease.
According to the fifth feature of the invention, the nozzle body is arranged beside a plurality of substrates in the processing container, and the drain port of the nozzle body is positioned outside the outermost one of the plural substrates. Thus it is possible to prevent the discharged dewdrops from being blown up to their adhesion to the substrate by air current in the processing container.
According to the sixth feature of the invention, the drain port is arranged multiple ports in the circumferential direction of the one end of the nozzle body.
According to the seventh feature of the invention, the drain port of the nozzle body is arranged so as not to face the substrate arranged in the processing container but to face the processing container""s inner wall on the opposite side of the substrate. Thus it is possible to restrict an occurrence of particles, allowing a uniform cleaning of the substrate to be progressed furthermore.
According to the eighth feature of the invention, the substrate processing apparatus further comprises a heater arranged in the nozzle body.
According to the ninth feature of the invention, there is also provided a substrate processing apparatus for supplying a substrate to be processed with processing gas and solvent vapor, comprising:
a processing container for accommodating the substrate therein;
a processing-gas supplier for supplying the processing gas into the processing container;
a solvent-vapor generator for generating the solvent vapor to be supplied into the processing container; and
a solvent-vapor nozzle arranged in the processing container and also connected to the solvent-vapor generator,
wherein the processing container has its upper part formed with an inner wall which is reverse V-shaped so as to descend from the central part of the processing container toward both ends thereof. With this constitution, the apparatus allows the dewdrops of the solvent-vapor, which adhere to the upside inner wall of the processing container, to flow into both sides of the apparatus via inclined faces forming the upper part of the processing container. Therefore, it is possible to prevent the dewdrops adhering to the upside inner wall from falling and adhering to the substrate. Thus it is possible to restrict an occurrence of particles, allowing a uniform cleaning of the substrate to be progressed furthermore.
According to the tenth feature of the invention, the processing container is provided, in an upper part thereof, with a heater. Therefore, it is possible to prevent the dewdrops from adhering to the upside inner wall of the processing container. Thus it is possible to restrict an occurrence of particles, allowing a uniform cleaning of the substrate to be progressed furthermore.
According to the 11th. feature of the invention, the processing container includes a container body having an upper part provided with a loading/unloading port for loading and unloading the substrate, a container cover for closing up the loading/unloading port through a seal member, and a locking mechanism for fastening the container body to the container cover disengageably. Therefore, it is possible to close up the processing container certainly, allowing the processing efficiency to be improved.
According to the 12th. feature of the invention, there is also provided a substrate processing method for processing a substrate to be processed, by supplying processing gas and solvent vapor to the substrate accommodated in a processing container, the method comprising the steps of:
researching on a pressure of the solvent vapor in a condition before the solvent vapor is supplied into the processing container;
supplying the solvent vapor into the processing container on the basis of the pressure of the solvent vapor. Therefore, it is possible to supply the solvent-vapor of an optimum amount without being influenced by the pressure in the processing container and also possible to process the substrate with the solvent-vapor and the processing gas.
According to the 13th. feature of the invention, the researching step for the pressure of the solvent vapor in the condition before being supplied into the processing container, is carried out by firstly measuring a temperature of the solvent vapor in the condition before being supplied into the processing container and secondly calculating the pressure from the detected temperature.
According to the 14th. feature of the invention, the researching step for the pressure of the solvent vapor in the condition before being supplied into the processing container is carried out by firstly measuring a temperature of a liquid solvent that can generate the solvent vapor to be supplied into the processing container and secondly calculating the pressure from the detected temperature.
According to the 15th. feature of the invention, the substrate processing method further comprises the step of supplying the processing gas into the processing container before supplying the solvent vapor into the processing container.
According to the 16th. feature of the invention, there is also provided a substrate processing method for processing a substrate to be processed, by supplying processing gas and solvent vapor to the substrate accommodated in a processing container, the method comprising the steps of:
supplying the processing gas into the processing container;
elevating a pressure of the solvent vapor before being supplied into the processing container higher than a pressure of the processing gas in the processing container; and
supplying the solvent vapor, whose pressure has been elevated higher than the pressure of the processing gas in the processing container, into the processing container.
According to the 17th. feature of the invention, the substrate processing method further comprises the step of controlling the pressure of the solvent vapor so as to be higher than a pressure of an atmosphere in the processing container, under condition that the pressure of the solvent vapor before being supplied into the processing container becomes higher than the pressure of the processing gas in the processing container.
According to the 18th. feature of the invention, the step of controlling the pressure of the solvent vapor so as to be higher than the pressure of the atmosphere in the processing container is carried, in a closed space where the solvent vapor before being supplied into the processing container is present, by releasing the closed space for a constant period to discharge the solvent vapor of a constant quantity from the closed space so that the pressure of the solvent vapor becomes less than a first pressure which is higher than the pressure of the processing gas in the processing container.
According to the 19th. feature of the invention, there is also provided a substrate processing apparatus for processing a substrate to be processed, by supplying processing gas and solvent vapor to the substrate accommodated in a processing container, the apparatus comprising:
a processing-gas supplier for supplying the processing gas into the processing container;
a solvent-vapor generator for generating the solvent vapor to be supplied into the processing container; and
a pressure researcher for researching a pressure of the solvent vapor in the solvent-vapor generator.
According to the 20th. feature of the invention, the pressure researcher includes a temperature detector for detecting a temperature of the solvent vapor in the solvent-vapor generator and a pressure calculator for calculating a pressure of the solvent vapor in the solvent-vapor generator from the detected temperature.
According to the 21st. feature of the invention, the pressure researcher includes a liquid-temperature detector for detecting a temperature of a liquid solvent in the solvent-vapor generator and a pressure calculator for calculating a pressure of the solvent vapor in the solvent-vapor generator from the detected temperature.
According to the 22nd. feature of the invention, there is also provided a substrate processing apparatus for processing a substrate to be processed, by supplying processing gas and solvent vapor to the substrate accommodated in a processing container, the apparatus comprising:
a processing-gas supplier for supplying the processing gas into the processing container;
a solvent-vapor generator for generating the solvent vapor to be supplied into the processing container;
a first opening/closing unit interposed in a supply pipeline that supplies the solvent vapor generated in the solvent-vapor generator into the processing container;
a second opening/closing unit interposed in a discharge pipeline branching from the supply pipeline on the upstream side of the first opening/closing unit;
a pressure researcher for researching a pressure of the solvent vapor in the solvent-vapor generator; and
a controller for controlling respective opening/closing operations of the first opening/closing unit and the second opening/closing unit on the basis of a detection signal outputted from the pressure researcher.
According to the 23rd. feature of the invention, the controller controls the opening/closing operation of the second opening/closing unit on the basis of the detection signal so as to maintain the pressure of the solvent vapor within a constant range.
According to the 24th. feature of the invention, there is also provided a substrate processing apparatus for processing a substrate to be processed, by supplying processing gas and solvent vapor to the substrate accommodated in a processing container, the apparatus comprising:
a processing-gas supplier for supplying the processing gas into the processing container;
a solvent-vapor generator for generating the solvent vapor to be supplied into the processing container;
a first opening/closing unit interposed in a supply pipeline that supplies the solvent vapor generated in the solvent-vapor generator into the processing container;
a second opening/closing unit interposed in a discharge pipeline branching from the supply pipeline on the upstream side of the first opening/closing unit;
a temperature detector for detecting a temperature of the solvent vapor in the solvent-vapor generator; and
a controller for controlling respective opening/closing operations of the first opening/closing unit and the second opening/closing unit on the basis of a detection signal outputted from the temperature detector.
According to the 25th. feature of the invention, the controller controls the opening/closing operation of the second opening/closing unit on the basis of the detection signal so as to maintain the temperature of the solvent vapor within a constant range.
According to the 26th. feature of the invention, there is also provided a substrate processing apparatus for processing a substrate to be processed, by supplying processing gas and solvent vapor to the substrate accommodated in a processing container, the apparatus comprising:
a processing-gas supplier for supplying the processing gas into the processing container;
a solvent-vapor generator for generating the solvent vapor to be supplied into the processing container;
a first opening/closing unit interposed in a supply pipeline that supplies the solvent vapor generated in the solvent-vapor generator into the processing container;
a second opening/closing unit interposed in a discharge pipeline branching from the supply pipeline on the upstream side of the first opening/closing unit;
a temperature detector for detecting a temperature of a liquid solvent in the solvent-vapor generator; and
a controller for controlling respective opening/closing operations of the first opening/closing unit and the second opening/closing unit on the basis of a detection signal outputted from the temperature detector.
According to the 27th. feature of the invention, the controller controls the opening/closing operation of the second opening/closing unit on the basis of the detection signal so as to maintain the temperature of the liquid solvent within a constant range.